"Those building the biblical Tower of Babel, intending to reach heaven, did not know where heaven was and hence when the project would be finished, or at what cost. Those setting out to solve the climate change problem now are in the same position. If we were to spend 10 or even 100 trillion dollars mitigating carbon dioxide (CO2) emissions, what would happen to the climate? If we canít evaluate whether reversing climate change would be value for money, why should we bother, when we can clearly identify many and better investments for such huge resources? The forthcoming Paris meeting on climate change will be setting out to build a modern Tower of Babel.Ē